Such a drive apparatus for a switch includes a controller and a drive circuit disclosed in, for example, Japanese Patent Application Publication No. 2014-16227. The drive circuit is configured to obtain a signal that is used to drive the switch and has a correlation with a physical quantity of a predetermined detection target. The drive circuit is also configured to perform a pulse-width modulation (PWM) of the obtained signal to thereby generate a cyclic pulse signal having a controlled duty factor. The drive circuit is also configured to transmit the cyclic pulse signal to the controller via at least one transmission terminal thereof, so that the controller obtains, based on the cyclic pulse signal, the physical quantity of the detection target.
The drive apparatus includes a first circuit region serving as a high-voltage region in which the drive circuit with the at least on transmission terminal is provided. The drive apparatus also includes a second circuit region that is electrically isolated from the first circuit region; the controller is provided in the second circuit region.